An engine compartment of a vehicle, such as a car, is normally covered by a bonnet. The bonnet is also known as hood, e.g., in American English.
A bonnet commonly comprises an inner panel and an outer panel attached to each other. The outer panel provides the bonnet with an outer surface, while the inner panel contributes to provide the bonnet with the desired mechanical properties.
There are a lot of demands and desires for a bonnet. It should have appropriate mechanical properties, e.g., panel rigidity, dent resistance, flexural rigidity and torsional rigidity. Further, the bonnet should be forgiving in case a vulnerable road user would be thrown onto the bonnet. In addition, it is desired that the bonnet does not weigh too much, since that would add to a total weight of the vehicle, e.g., increasing fuel consumption.
Patent document EP 2 692 615 A1 discloses a bonnet panel comprising an inner panel and an outer panel. The document EP 2 692 615 A1 further describes the above-mentioned mechanical properties.